The repetition of God’s name or of a mantra containing God’s name, otherwise known as japa, is a religious ritual, generally meant for the emancipation of the self. The present book on japa-yoga has not neglected this aspect. But, it is a more comprehensive and a broad-range book. That japa is a branch of yoga, an easily attainable one and simultaneously a very effective one, has been emphasized. The theory and methology of japa in Patanjala Yoga, in the Vedas, in the Vedanta and in the Tantra, in the perspective of knowledge and devotion, have clearly been outlined. The book has been divided into three Chapters. Chapter 1 expounds the theory of japa based on classical scriptures. Chapter 2 presents the practice of japa in a clearly graspable style, easy to be followed by the readers. Chapter 3 deals with the applications of japa for the uplift of human personality and spirituality, for attaining the liberation of the self, for mental peace and tranquillity, and for physical health inclusive of the prevention and treatment of diseases, both physical and mental. The last part of this book tries to explain the effects of japa-applications on a scientific footing, a successful attempt made for the first time.